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Gear Teeth Meshing + Movement 1

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UKIDIOT

Mechanical
Oct 13, 2004
36
I am trying to do to bevel gears meshing with movement in Unigraphics NX3. I'm starting out with doing 2 cylinders with an angled edge to get my diameters right etc. My boss wants to see it in motion. We don't have the motion license, but I can still do the vary constraints and it will move. My problem is that the cylinders are 90 degrees to each other and when I do the vary constraints it just rotates one clinder. Because it doesn't know that the other is supposed to rotate. I had to use a tangent constraint to get the to beveled edges tangent. Does anyone have any suggestions on how I can achieve this movement?
 
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The Bad news is...
I don't know if you can get the gear mechanism to work using the motion license. I don't think that it will work using mating conditions as you describe. The problem as I see it occurs when the contact passes from one tooth of the gear to the next tooth. If you need to precisely duplicate the meshing of gears in order to tune the performance of the shape of an involute gear tooth then stop reading here.

The good news may be...
You can mate each gear with an angular constraint relative to its rotational axis, possibly based on the mounting shaft. Having done so you can define the angle of orientation of either gear such that they appear to stay in mesh as they are rotated using a formula. If the driving gear is rotated through angle A and the driven is half its diameter then it rotates A*2 degrees. This can be done using expressions. By assigning the expression values above to the angular mating conditions you should be able to get the mechanism to update such that it will approximate one gear driving the other.

To go a step further set up an animation to update the expression by adding an expression called FrameNumber and using it to drive the angle formulas. You will probably have to experiment for a while and refer to the documentation to get it to work. The animation function is geared to output an mpeg file so that should impress the boss :)

 
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